Transient Film Boiling of Water on a Horizontal Wire

Abstract

This paper reports an experimental and analytical investigation of transient film boiling of water from a horizontal submerged platinum wire following a large step change in wire temperature. Experimental vapor growth rate data were obtained from high-speed motion pictures with pool temperatures very close to saturation and wire temperatures ranging from 1245 to 1739 deg F. An analytical solution for vapor growth rate which assumes the primary mode of heat transfer within the vapor to be conduction is presented. Heat transfer rates based on the characteristic vapor growth time were calculated from measured vapor formation data.

Natural Convection Film Boiling Heat Transfer

“…In a transient film boiling study, McLean et al (137) found a delay time of 20 to 256 ^sec before film boiling was established while pulse heating a fine wire. A similar result, using a step power input, was seen by Pitts et al (163,164). Both Cole (50) and Hall and Harrison (86) found that subcooling retarded the formation of film boiling during transient heating.…”

“…This expression gave values in good agreement with their exact numerical solution. A somewhat similar analysis for transient film boiling from a horizontal wire has been presented by Pitts et al (163,164). The influence of sinusoidal pressure fluctuations on film boiling has been calculated analytically by Burmeister and Schoenhals (40,41).…”

“…The effect of pressure oscillations was studied by Markels et al (130) and Di Cicco and Schoenhais (55). Pulse-heating studied wires (163,164) 28-and 30-gauge platinum 1 atm Transient film boiling wires study (50) 3 in. by 0.15 in.…”